Mobility aids such as wheelchairs and walkers are used by a significant portion of society. These mobility aids provide an important function for those they assist. In order to effectively serve this function, however, a mobility aid must be appropriately sized for the individual it is assisting.
Manufacturers of mobility aids address this requirement by making their mobility aids adjustable. A common approach is to provide multiple locations on a given structural member of the mobility aid where another member may attach. In this manner, a user can change the structural dimensions of the mobility aid by adjusting the attachment locations of various structural members.
As an example, two or more structural members of a device may be attached by fasteners (such as bolts) which fit within corresponding fastener openings on the structural members. Additional fastener openings on one or both of the structural members provide alternative coupling locations between the structural members. Changing fastener openings modifies the position of the members relative to one another, thus changing the dimensions of the device.
A drawback of this simple approach is the cumbersome nature of the process. To change fastener openings on the structural members, the user must disassemble and remove the fasteners, usually a nut-bolt-washer combination. Often, multiple fasteners must be removed to facilitate the change. Once this is accomplished, the user must align the desired fastener openings on the corresponding members, hold the various parts and the structural members in place, and insert and reassemble the fasteners. A common result is for a washer to slip out of alignment or fall out of the assembly during the process.